station_number	A six-digit number normally referred to as the "MEDS" station number. Presently "MEDS" station numbers are only 5 digits, the six digit field will allow for future expansion.	NUMBER (6) Foreign Key
benchmark_number	A 16-character field to indicate the identification stamped on the physical monument.	VARCHAR2 (16) Foreign Key
unique_number	An 8 character NRCan style unique identifier for the monument. ** Note : Although the year identifier i the unique number is only 2 digits, the century is covered by the character used to identify the province. i.e. the province identifier will change for BMs installed in the year 2000.	NUMBER (6)
benchmark_elevation_id	Autogenerated number unique to each elevation.	VARCHAR2 (8)
account	This field is system set with user account info for update and delete privileges.	VARCHAR2 (16)
DBE_TIME	Database Entry Time - System set.	DATE
DBU_TIME	Database Update Time - System set.	DATE
status	A field to identify whether the following elevation is "Active" or "Historical" in reference to the datum_name.	VARCHAR2 (16) check list
datum_name	A name that will be associated with this datum of elevations.	VARCHAR2 (16)
dn_epoch	The year the "datum_name" was first established.	NUMBER (4) Default value 9999 to indicate no value has been assigned or is applicable
elevation	The elevation of the monument referenced to the "datum_name".	NUMBER (8,3)
elevation_acc	A number indicating the accuracy of the "elevation".	NUMBER (4,3) Default value is 9.999 to indicate no value has been assigned
hyd_corr	The Hydraulic Correction factor established under IGLD (1985).	NUMBER (6,3) Default value is 9.999 to indicate no value has been assigned
hyd_corr_epoch	The year the "hyd_corr" factor came into effect.	NUMBER (4) Default value is 9999 to indicate no value has been assigned or is applicable
holding_benchmark	A Yes/No indicator as to whether the "elevation" is used as a holding benchmark for the "datum_name".	VARCHAR2(16) Default value NO check list

Note: For a unique station number and benchmark number there can be multiple entries for each of the datum names although only one can be active. As revised elevations come in for a particular datum name, it is necessary to add the elevation as a new one to keep the old record. The software will automatically change the previously active entry into historical for that datum name. This will maintain in the database a history of the various elevations for a monument.

Tables and Columns